The proposed studies basically include evaluation of adhesion, motility, deformability and chemotaxis of normal and abnormal granulocytes, in vivo and in vitro. The studies at the present time, and in the predictable future may be divided into three closely related sets of experiments: (1) Determination of the mechanism of the acute granulocytopenia and monocytopenia which occur immediately after infusion of high dose microtubule inhibitors such as vincristine, vinblastine and colchicine. (2) Evaluation of the mechanism and complications, both acute and chronic, of hemodialysis leukopenia, including modification/obviation of the leukopenic reaction.(3) Functional evaluation of granulocytes harvested from donors for leukocyte transfusion into patients on high does anti-leukemic therapy. Three methods of cell collection are under study: (a) nylon fiber filtration leukaphersis; (b) intermittent flow centrifugation; (c) continuous flow centrifugation. BIBLIOGRAPHIC REFERENCES: 1) Fehr, J., Craddock, P.R., Brigham, K.L., Jacob, H.S.: Pulmonary capillary leukostasis: A complement (C') mediated complication of hemodialysis. Proc. International Soc. Nephrology. 1975 2) Bowers, T.K., Craddock, P.R., Jacob, H.S.: Complement (C') induced granulocyte paralysis due to drug allergy. Clin. Res. 23:489 (1975).